Apparatus for sharpening drill bits are known. In the patent to Adams, U.S. Pat. No. 2,109,309 there is shown a quite complex drill sharpening apparatus which provides cams for simultaneously advancing the drill bit toward the grinding wheel and for rotating the drill bit about an axis transverse to the drill. This structure is quite complicated and requires precision machining to insure proper sharpening of the drill bit. The U.S. patent to Studler, U.S. Pat. No. 2,797,538 shows an apparatus for holding a tool to be sharpened. The Studler apparatus allows for angular adjustment only about an axis normal to the axis of the tool being sharpened and again requires many parts to be precision-machined to insure correct sharpening of the tool. The patent to Mueller, U.S. Pat. No. 2,958,167 shows a device similar to that shown by Studler except for variations in the chuck and other small features which are not pertinent to the present invention. The device shown by Bernard et al, U.S. Pat. No. 4,001,975 shows a complete drill bit sharpening device wherein the drill bit is placed into a chuck in one part of the device and aligned; the chuck is then moved to a holder at another part of the apparatus for sharpening. This apparatus is quite expensive and complex.
Chucks for holding a drill bit are known generally. The U.S. patent to Fishwick, U.S. Pat. No. 2,670,215 provides a chuck having jaws which ride in grooves in a cylindrical element in the inner part of the chuck, and which provides springs for rotating the jaws so as to open them to receive the shank of a drill bit. The patent to Wahl, U.S. Pat. No. 4,266,789 shows a chuck similar to that shown by Fishwick. Both of the chucks to Fishwick and Wahl utilize jaws having slanted surfaces which coact with a conical surface on the nut of the chuck. This arrangement does not allow a high degree of alignment precision, with low cost production methods.